Installation steps:
Started Win10, plugged the eGPU in the TB3 port, drivers installed automatically, restarted the system and additionally installed NVIDIA drivers from their homepage. Everything worked right out of the box, including external and internal screens. I am also using an HP Thunderbolt Dock G2 in the second TB3 port for charging, peripherals, headset etc. No problem with input lag or anything else.

Comments:
Initially I wanted the eGPU for occasional gaming when travelling. However, everything runs so smoothly that I am completely replacing my old gaming rig (i7 2600K, 16 GB RAM, RX 580) with the eGPU setup. I am currently only playing Squad v12, which is always at the manually set 60 FPS cap. The eGPU improved my workflow, since I do not need to change the PC between working and gaming; the setup is also not as noisy as my desktop PC.

I was also able to unlock my 8250U CPU with Throttlestop, and reached 1772 in Cinebench R20 and 724 in Cinebench R15. However, for Squad v12 the original settings were sufficient. The CPU runs at 14W @56-60 °C without unlocking, which is sufficient for 60 FPS in Squad v12. The CPU is also undervolted (-150 mV Core and -85 mV Cache) and I am using the laptop with a cooling pad for longer gaming sessions.

We’d love to see photos of this eGPU. How’s the temps and noise? I installed a Gigabyte RX 580 from the Gaming Box and it’s amazingly quiet. That card has no shroud and an oversized fan so heat dissipation is very effective inside the AMP BOX Mini.

I added a link for some photos of the setup (see edit). Temperature is a problem with this card: while gaming the temperature reaches 80 °C, if the enclosure is closed. If I leave it open, the temperature is in the mid 60s °C. I could add a small fan that pushes air into the enclosure, which might help cooling. Otherwise, the enclosure is really great, it fits in every bag and is not too heavy to carry for a lengthy period. The setup is also very quiet (the laptop cooling pad is the loudest part). With a normal headset, I can't hear any fan!

Edit: I just placed a case fan from my desktop next to the enclosure and temps were just fine during heavy loads (mid 60s °C). I just ordered USB powered fans, which only switch on when the enclosure is running (plugged into the enclosure's USB port). The alternative would be to buy the Sonnet 350W enclosure, which is just a tad more expensive. However, I really like the size of the AMP Box Mini, so I will stick to it. The best modding would be to add a small fan inside the enclosure, but I think there is no adaptor for the 8 Pin PCIe connector (6 pin to 2x 8 pin could be used to have an additional 8 pin PCIe power connector available in the case) to drive a fan...